Method for repairing fracture of main shaft of kneading machine

The invention discloses a method for repairing the fracture of a main shaft of a kneading machine. The method comprises the following steps of: placing the main shaft on a lathe, chucking the non-broken end by a three-jaw chuck, supporting the broken end by a center frame, and aligning the broken end; flattening the broken end by turning through a turning tool; slightly thinning the part of a neckjournal by turning through the turning tool, and turning an external thread, a connecting thread shown in Figure 1; taking a steel rod which is made of the same material as the main shaft and is larger than a broken abutting joint shaft head, and taking the turned external thread fixed on another lathe as a reference internal thread, the length of which is slightly longer than the external thread; thinning the outer circle of the abutting joint shaft head by turning, wherein the diameter of the abutting joint shaft head is slightly larger than the original size, the length of the abutting joint shaft head is slightly